1. Field of the Invention
The invention relates to a method for operating a motor vehicle having an active roll control system and an air suspension system.
2. Description of Related Art
Roll control systems in motor vehicles counteract a rolling movement of the vehicle when unevenness on the road or cornering causes a wheel to experience spring compression or spring extension. The roll control system transmits vehicle body movement, generated by spring compression or extension, to the opposite side of the vehicle wherein a torsional property of the roll control system causes damping and deceleration of the transmission. Roll control systems can be provided on the front axle, the rear axle, or on the rear and front axles of the motor vehicle.
Active roll control systems (ARC) are becoming increasingly widespread in vehicles with a high center of gravity and in sport vehicles. In this context, the rolling properties of the vehicle are adapted to different driving situations and driver preferences by changing the mechanical transmission behavior of the roll control system. For example, a “more direct” or “harder” transmission may be desired in a “sport” operating mode, or the understeering behavior of the motor vehicle during cornering may be influenced.
In the motor vehicle industry, air suspension systems constitute a widespread alternative to coil springs and leaf springs. These systems include air-filled bellows that bring about the desired spring effect. A level of the air spring can also be changed by changing the air pressure of the air in the bellows, which can be used, for example, for lowering the bodywork when traveling at a high speed, or to permit easier entry into the motor vehicle. The volume of the air spring can be changed by, for example, connecting an additional volume through a valve. In this way, the spring constant of the air spring can be changed, and in the case of an increase in volume it is reduced, which results in softer suspension. An air suspension system with an adaptable spring constant can be used for convenience functions similar to those explained above for active roll control systems.